Recently, with the development of information processing technology, there has been remarkable progress in virtual reality (VR) technology, particularly in head-mounted display (HMD) technology. By applying HMD technology to a game, for example, and having a user wear an HMD on one's head, the user becomes able to experience an immersive game. In such a game, a more immersive experience is made possible by controlling the game using not only an ordinary game pad, but also bodily movements (for example, see Patent Literature 1 below).